Which of the following best describes why the GTP produced in the conversion of succinyl-CoA to succinate in the TCA cycle is equivalent to ATP?
A) amino group on the C-2 position of GTP can be transferred to the C-6 position to form ATP
B) free energy of hydrolysis of the g-phosphate of GTP is equivalent to that of ATP
C) GTP is used in biosynthetic pathways such as protein synthesis
D) salvage pathway involving phosphoribosylpyrophosphate (PRPP) can be used to regenerate GTP

Question

Quizplus · Accepted Answer

The free energy of hydrolysis of the gamma-phosphate of GTP is equivalent to that of ATP, making them energetically interchangeable in cellular processes.  All cells contain enzymes for the interconversion of various nucleoside mono- and diphosphates into nucleoside triphosphates such as ATP. Thus, the g-phosphate of GTP is energetically equivalent to the same phosphate in ATP. GTP can therefore, drive the synthesis of ATP from ADP via the action of nucleoside diphosphokinases.

Which of the Following Best Describes Why the GTP Produced